<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let p = new Promise((resolve,reject)=>{
            resolve("成功")
        })
        let t = p.then((value)=>{
            console.log('成功时执行',value);
        },(reason)=>{
            console.log("失败时执行",reason);
        })
        console.log(t);
    </script>
</body>
</html>